Starting IFN

[jetstream]

I think there could be fellow observers that are interested in trying to see some very faint shades of nebulosity. There are optimum scopes for this but just try what you have, get the exit pupil over 5mm, from dark transparent skies with a widish TFOV.

These sketches are borrowed from Mel Bartels which I hope is OK.

These first two sketches show some IFN that I can see portions of with the excellent DSO neb scope -SW120ED and a mid range EP, the Vixen 42mm LVW.

The Vega sketch shows a spur near it that is relatively easy to see, if you can keep Vega at bay.  The second is some easyish shades near the Double Double, I have been observing these 2 for a couple of years. My prism diag kills these feature, the cheap but vg SW mirror diagonal works well.

Hopefully members can enjoy some success like I have.

 

Edited January 22, 2020 by jetstream

[jetstream]

https://www.bbastrodesigns.com/Herschels Ghosts.html

[John]

Integrated Flux Nebulae is a new term to me Gerry but its always nice to learn about new stuff

Thanks for the link as well

[scarp15]

That is an informative - revised up to date article by Mel Bartels Gerry thanks. Integrated Flux Nebulae, we had discussed this at length before a few years ago. I think back then I recall having a good go to trace the IFN that is in the vicinity of M81, M82 and sensing at the time that in the right circumstance and based on Mel Bartels drawings as reference it was possible to visually detect, at least aspects. At the weekend it was the Pleiades Bubble that with conviction was visually apparent. I did not study this outer area too much as I was more focused on the immersive Merope and associated nebulae. The large exit pupil 7.73mm / 1.4 degree field, coupled to the excellent transmission of the paracorr enabled these features to become quite bright and engaging. 

Perhaps something to consider exploring for again on dark sky trips and consider aiming to detect the spur you had described near to Vega.

Edited January 22, 2020 by scarp15

[jetstream]

 

This is one currently visible, I have been studying some of these features a bit lately.

[Littleguy80]

Excellent thread, Gerry. For those of us lucky enough to have a choice of scopes, what would suggest as criteria for choosing which scope to use? My inclination would be to use my 10" dob but wondered if the wider FOV of my 80mm frac would be better for targets such as these?

[scarp15]

Yes definitely I would think your 10" dob, 40mm eyepiece Neil.

[Littleguy80]

31 minutes ago, scarp15 said:

Yes definitely I would think your 10" dob, 40mm eyepiece Neil.

Thanks for confirming, Iain. It seems like aperture would be needed. 

[jetstream]

3 hours ago, Littleguy80 said:

use my 10" dob

yes, with a but!

Try your 80mm frac too Neil, nothing to lose all to gain!

My 90mm triplet APO falls down on these, the SW120ED doublet is VG and the triplet TSA 120 is superb. My 24" is out, the 15" can catch the edges, and the 10" is good to vg, the 200mm f3.8 excellent.

Try everything

[Littleguy80]

9 minutes ago, jetstream said:

yes, with a but!

Try your 80mm frac too Neil, nothing to lose all to gain!

My 90mm triplet APO falls down on these, the SW120ED doublet is VG and the triplet TSA 120 is superb. My 24" is out, the 15" can catch the edges, and the 10" is good to vg, the 200mm f3.8 excellent.

Try everything

Thanks Gerry. Sounds like it’s fast focal ratio with moderate aperture for best results. I’ll certainly have an experiment and report back  

[Nyctimene]

My 8" f/4 Hofheim Instruments traveldob, paired with the 30mmf/77° Wild Heerbrugg (TFoV 2.89°, mag 27x, EP 7.5 mm) might be a weapon of choice, along with the 2" Astronomik UHC. I'm afraid, that the atmosphere will not be cooperative. It contains, here in SW Germany, a lot of humidity now, even in the winter months, resulting in poor transparency. But I'll give it a try. Thanks, Gerry, for the thread and the link.

Stephan

[jetstream]

16 hours ago, Nyctimene said:

My 8" f/4 Hofheim Instruments traveldob, paired with the 30mmf/77° Wild Heerbrugg (TFoV 2.89°, mag 27x, EP 7.5 mm) might be a weapon of choice, along with the 2" Astronomik UHC. I'm afraid, that the atmosphere will not be cooperative. It contains, here in SW Germany, a lot of humidity now, even in the winter months, resulting in poor transparency. But I'll give it a try. Thanks, Gerry, for the thread and the link.

Stephan

Great telescope for this Stephan as well as the eyepiece and yes the humidity might be an issue. Here we had fog the other day- not typical when the temps are supposed to be much lower and it does hurt DSO viewing. On another note I've not used a filter for these faint nebs.

I think that what we will see of these IFN or whatever they are are fairly individual ie I don't see exactly what Mels sketches as a whole- only parts of it. It is possible each observer may pick up different bits of it or even the whole thing. The Merope area is a vg place to start, around the end of the fan.

Eagerly waiting reports!

Edited January 24, 2020 by jetstream

[ollypenrice]

On 22/01/2020 at 16:45, John said:

Integrated Flux Nebulae is a new term to me Gerry but its always nice to learn about new stuff

Thanks for the link as well

It's generally an imager's obsession, John. In the early days the trick was to get it at all and then trying to get it's colour drove us all to distraction! It turns out to be a brownish colour. We think. 😁

I've never tried for it visually but why not? Useful pointers from Jetstream. Thanks.

Olly

[scarp15]

Yes, no need for a filter but absolutely humidity is the factor, has to be a dry and transparent night, perhaps with a light breeze to. This weekend is disappointing, no hope no chance just cloud cover. Therefore dark sky periods, later in February and Ursa Major will be gaining due south, M81, M82 will be elevated high. The formation of Integrated Flux Nebula is encountered in the region of M82 and might be worth exploring for if circumstances are right. Mel Bartels sketch conveys an indication, my vague recollection is that an aspect based on this sketch may be detectable, could be interesting to factor in for next month.

[scarp15]

Here are two more drawings borrowed from Mel Bartels collection and referencing the comments made above. Describing picture one, as the base of the broad bands is a bright area. Picture two the IFN entwined with the two galaxies.